Will Larson's Web Page

Vox EU Article

NBER working paper released

http://www.nber.org/papers/w15455

Is Newer Better? Penn World Table Revisions and Their Impact on Growth Estimates

Simon Johnson, William Larson, Chris Papageorgiou, Arvind Subramanian

This paper sheds light on two problems in the Penn World Table (PWT) GDP estimates. First, we show that these estimates vary substantially across different versions of the PWT despite being derived from very similar underlying data and using almost identical methodologies; that this variability is systematic; and that it is intrinsic to the methodology deployed by the PWT to estimate growth rates. Moreover, this variability matters for the cross-country growth literature. While growth studies that use low frequency data remain robust to data revisions, studies that use annual data are less robust. Second, the PWT methodology leads to GDP estimates that are not valued at purchasing power parity (PPP) prices. This is surprising because the raison d’etre of the PWT is to adjust national estimates of GDP by valuing output at common international (purchasing power parity [PPP]) prices so that the resulting PPP-adjusted estimates of GDP are comparable across countries. We propose an approach to address these two problems of variability and valuation.

Finished the new and improved EPI!

I just finished constructing a new and improved Export Price Index for U.S. counties and cities. The EPI is a Laspeyres-type price index measuring the terms of trade of a region. The weights are from QCEW data, and the prices come from PPI (SIC), PPI (NAICS), PPI (Commodity), and the CPI (urban consumers). For more info, check out http://papers.ssrn.com/sol3/papers.cfm?abstract_id=9252.

Documentation to follow at some point…

Luck Adjusted Pitching

I’ve been working on creating some statistics for pitchers that take out some of the effects of “luck.”  This allows pitchers to be more accurately valued and ranked according to underlying ability. The methodology is very simple, but it’s interesting how such simple estimates can tell you when a pitcher is for real (Tim Lincecum), if he’s just lucky as heck (Cliff Lee), or if he’s got the short end of the stick (Javier Vazquez).

Here is a very rough draft of the methodology
Here is an accompanying table in PDF format.
Here is an accompanying table in XLS format.

This is what Econ PhD candidates do in their spare time during the baseball offseason…